Microstructure evolution during laser surface cladding and remelting of Al-10wt%Bi-10wt%Cu

Laser surface cladding and remelting provides a route to synthesize functional microstructures on the surface of structurally important materials. Alloys containing fine soft particles embedded uniformly in a hard matrix find applications as bearing materials with low friction coefficient. Elemental powder mixtures are used to clad Al + 10wt%Cu + 10wt%Bi on the surface of aluminium base metal in both single and multi-track mode at two different cladding speeds. The clad layers are remelted at speeds varying from 500 mm/min to 2500 mm/min to simulate different solidification speeds. Microstructure evolution during the process is studied by measuring particle size distribution and alignment to identify optimum processing conditions. Pin on disc experiments show a low friction coefficient of 0.22 for the samples remelted at 2500 mm/min.